China
Africa
Explore chapters and articles related to this topic
Instrumental Vaginal Delivery
Published in Sanjeewa Padumadasa, Malik Goonewardene, Obstetric Emergencies, 2021
Malik Goonewardene, Sanjeewa Padumadasa
The vacuum cup should be applied between contractions, and over the flexion point on the fetal skull, which is 3 cm anterior to the posterior fontanelle. As the diameter of a vacuum cup as well as the distance between the anterior fontanelle and the flexion point is about 6 cm, the application of the cup with one of its edges at the posterior fontanelle and the other edge about 3 cm away from the anterior fontanelle will ensure its correct application (Figure 9.17). Proper application of the vacuum cup over the flexion point ensures that the narrowest anteroposterior diameter of the fetal skull, i.e. suboccipito-bregmatic, presents at the maternal pelvis. It is important to note that the flexion point may be located more posteriorly along the sagittal suture than it appears, especially in deflexed OT and OP positions of a vertex presentation.
Operative delivery
Published in Louise C Kenny, Jenny E Myers, Obstetrics, 2017
For successful use of the ventouse, determination of the flexion point is vital. This is located at the vertex, which, in an average term infant, is on the saggital suture 3 cm anterior to the posterior fontanelle and thus 6 cm posterior to the anterior fontanelle. The centre of the cup should be positioned directly over this, as failure to do so will lead to a progressive deflexion of the fetal head during traction, and an inability to deliver the baby safely.
Ventouse Delivery
Published in Gowri Dorairajan, Management of Normal and High Risk Labour During Childbirth, 2022
Principals of vacuum delivery: The metal cups work in the principle of producing chignon, which is scalp oedema generated by slow suction. The widest part of the cup not being at the outer rim gives a firm entrapment of the chignon to allow steady traction.The silastic cup does not form a chignon. Here, the cup being silastic gets held onto the scalp by a firm vacuum created at the interface of the scalp and the cup.The most important principle is that the cup should be applied at the flexion point.Flexion point (Figure 15.1c) is a point at the midline on the sagittal suture 3 cm in front of the lambda or 6 cm behind the bregma. Traction on this point flexes the head as it descends along the curve of Carus. If wrongly applied, the head will start extending and get stuck or the vacuum cup will slip. In the occipitotransverse position, the cup is in the middle of the vagina, closer to the occipital side. The cup should be applied in the vagina much posterior in the occipitoposterior position as the flexion point is far posterior.The Malmstrom-like cup should not be used for rotation.The posterior type of Bird cup is preferred for rotation of ROP position.Vacuum extraction has to be synchronized with maternal efforts. So, the vacuum traction is applied at the peak of a contraction with maternal efforts.The rotation should never be deliberately done with the cup. That means we should not twist or rotate the traction rod as we pull. Twisting rotational force can cause spiral avulsion of the scalp.With metal cups, the vacuum pressure should be raised gradually over 2 minutes starting from 0.2 kg/cm2 to 0.8 kg/cm2 to allow the chignon to form. Whereas, with the silastic cup, it can be immediately raised to 0.8 kg/cm2.The traction force should always be perpendicular to the cup. Lateral or rocking movement or rotational movement will result in cup detachment and/or scalp avulsion.
Laryngoscopes for difficult airway scenarios: a comparison of the available devices
Published in Expert Review of Medical Devices, 2018
The GlideScope video laryngoscope (Verathon, Bothell, WA, USA) was first used in adult intubation in 2001, and the first pediatric intubation took place in 2005. Currently, there are several models of the GlideScope device: the original GlideScope®, the GlideScope Ranger®, and the GlideScope Cobalt® (Figure 4). In GlideScope, the blade is angled to 60° with an in-built reusable video camera at the flexion point, allowing real-time visualization of the image of the end of the blade on the attached monitor. The camera is placed approximately halfway along the integrated anti-fog system [56]. The view from the camera is illuminated by a light-emitting diode, located near the end of the blade. Reusable blades for the original GlideScope® are available in sizes from 2 to 5, with the maximum height of 14.5 mm. During the intubation procedure, the endotracheal tube is passed styletted to match the blade curvature, often assuming the shape of a hockey stick. Lee et al. [57] suggest that a 70° angle stylet is superior to a 90° angle stylet for GlideScope® intubation. Moreover, the use of GlideScope for endotracheal tube placement reduces the incidence and severity of postoperative sore throat compared with the Macintosh laryngoscope [58].